In a heat exchanger disclosed in Japanese Examined Utility Model Publication No. H7-3173, one end of the header, and more specifically, the lower lid closing off the lower end of the header, is provided with a collar, a fitting portion projecting out at the upper surface of the collar and a retaining projection projecting out at the lower surface of the collar, and the heat exchanger is mounted at a vehicle body by fitting the retaining projection at a retaining hole constituted of a vibration-damping rubber provided at the lower mounting plate secured to the vehicle body.
In addition, Japanese Unexamined Utility Model publication No. H5-45482 discloses a structure achieved by forming a side projection as an integrated part of a lid closing off the opening at the lower end of the header pipe and providing an insertion pin at the lower surface of this side projection so that the insertion pin is offset from the center of the axis of the header pipe along a specific direction. By adopting this structure, the position of the insertion pin can be selected freely over a wide range.
The invention disclosed in Japanese Unexamined Patent publication No. H5-332693 achieves simplification in bracket mounting by providing a male screw that is set erect at the outer end surface of a header cap closing off the lower end of the header pipe.
The invention disclosed in Japanese Unexamined Patent Publication No. H 9-26282 is provided with a lid assuming a structure different from that of the lid having the side projection disclosed in Japanese Unexamined Utility Model Publication No. H6-45482 mentioned above. The lid disclosed in this publication has an inward projection and a side projection provided as an integrated part of the inward projection and projecting out along the direction of the width of the tubes and is formed as a block body achieving a roughly L-shape in the plan view.
As an examination of the examples quoted above reveals, since the lower end of a heat exchanger mounted at a vehicle body is set near the vehicle body side panel, a means for retention to retain the heat exchanger at the vehicle body panel is provided at the lid that closes off the lower end of the tubes of the heat exchanger. However, it is not desirable to provide a means for retention such as a pin as an integrated part of the lid, since the pin tends to become skewed during the brazing process to such an extent that, in extreme cases, it can no longer be fitted at the mounting hole at the vehicle.
In addition, reflecting the increasing need for a reduction in the engine room space in recent years, the space available for mounting the heat exchanger has become smaller, thereby necessitating reduced dimensions in the heat exchanger.
Thus, the heat exchanger itself must become more compact. The lid (cap), which is normally manufactured through cold forging or the like, must be washed after it is formed since impurities such as the mold releasing agent and the press oil adhere to the manufactured cap. If the end of the cap is formed in a flat shape in this situation, a problem arises while washing the cap in that it may not be washed thoroughly. In addition, if the lid is formed in a flat shape, it is necessary to assure a specific thickness for the lid so that it can withstand pressure applied to the lid.
Accordingly, an object of the present invention is to provide a heat exchanger achieving a reduction in the header pipe dimensions and having a cap with a sufficient degree of strength against pressure, which can be washed thoroughly when washing the lid.